I have never tried this before, but we'll see if it works out! NOTE: Have sold 1 set of 3 cars, as reflected in the photos. 4 left. Ignore the 'eBay count'.
I have 15 automobile kits and my idea is to sell them in groups of 3. Each 3 is the same price, $22.50, plus the shipping charge. You can buy the cars already in a group, or you can pick any 3 autos from these groups. As these cars sell, I will modify the posting to remove those that are gone. If one person wants to buy all the cars, he can and the sale is removed. If he wants 2, 3 or 4 groups, that is fine as well.
The groups all contain identical cars or cars in the same category. Like 1 group is 3 identical Fords, the others have similar Pick-up trucks or even a group of 3 school buses. Your choice is to keep an existing group or make a group of your own-- and I will modify the post to reflect whatever is left. I am going to list this as a group of 5 items for sale and if you buy more than a single group, I will modify the shipping charge to reflect the sale as being shipped in a single container.
The key to this is you need to send me a message (Contact Seller) listing cars you want. When you make the purchase I can modify the images remaining in the post.
I will definitely answer questions about this, in eBay messages.